The desirability of conveyor table capable of steering an article in a desired direction has long been recognized. Such a conveyor is known from U.S. Pat. No. 4,180,150. In that reference, by turning rotation-symmetrical conveyor members about a corresponding second line perpendicular to the plane of transport, the direction of transport of the conveyor members can be adjusted, so that the articles can be displaced in a plurality of directions along the conveyor members and thus along the transport surface. The position of the axis of rotation of each conveyor member corresponds in each case with the direction of displacement of the portion of an article that rests against that conveyor member.
In the known conveyor table the conveyor members are mounted on the support construction, standing free therefrom. This carries with it the drawback that a relatively large number of conveyor members are required to ensure that flexible articles, such as sheets of paper, and also small articles, can be conveyed over the table without getting between the conveyor members by bending or falling. A further drawback is that parts of the body of a person operating the table can be caught between the conveyor members. Yet another drawback is that the control means are arranged above the support construction, whereby these means may get contaminated relatively quickly and constitute a hazard for users of the conveyor table. Furthermore, the conveyor members suspended above the support construction form obstacles which make it more difficult to clean the conveyor table.
U.S. Pat. No. 3,828,917 discloses a conveyor table with spherical conveyor members each retained in position by an opening in a guard plate and each resting on a separate, corresponding disc which is rotatable about an axis perpendicular to the guard plate. The discs are suspended in a support construction which can be displaced relative to the guard plate along a circular path parallel to the guard. Drawbacks of that conveyor table are that great friction will occur between the conveyor members and the edges of the corresponding openings, that the bearings of the discs will be very heavily loaded by the articles to be conveyed, and that controlled, quick changes of the rate and direction of transport are not possible owing to mass inertia of the transport members, each being in contact with the corresponding disc only through their own weight.